Driver detection and recognition of lineside signals and signs at different approach speeds

A study was carried out using simulation to investigate driver responses to lineside signals and signs at various approach speeds. The objectives of the study were: (1) to find out whether train speed would significantly affect signal/sign reading; (2) to examine at which point certain types of signs or signals could be detected or recognised, and (3) to determine a speed cut-off level above which certain types of signs or signals are no longer recognisable or detectable. Fifty-seven train drivers from 12 Train Operating Companies in the UK participated in the trials. Twenty different types of lineside signs and ten types of signals were tested under six different approach speeds ranging from 100 to 350 km/h (62–218 mph). Driver performance measures were ‘time remaining to the signal/sign’ at the point of detection or recognition, and reading error rate. The results showed a significant influence of train speed on driver responses to lineside signals/signs and demonstrated a non-linear relationship between driver responses to signals/signs and approach speed. This has been used to estimate a maximum approach speed limit within which a specific signal or sign can be correctly detected or recognised. The findings and implications of the study are discussed in the paper.     

中法交流:一树百获

华揽洪(LéonHoa),吴良镛,崔恺,栗德祥,张祖刚,齐欣,单黛娜,这七位建筑师属于三代,年龄从45至92岁。他们是这期特刊的主要人物。为什么把他们放在一起,他们之间有什么共同之处吗?他们中的几个人可以讲流利的法语,在法国曾居住、工作、学习过,但这不是把他     

LC–MS/MS characterization,antidiabetic, antioxidative,and antibacterial effects of different solvent extracts of Anamur banana (Musa Cavendishii)

Food Science and Biotechnology - The main objective of this study was to examine the phenolic compounds and the antibacterial, antioxidant, anti-α-glucosidase and anti-α-amylase...     

A Rheological Study of Mechanical Dough Development and Long Fermentation Processes for Cream-Cracker Dough Production

In the manufacture of products such as bread and cream-crackers mechanical development and long fermentation processes are used to develop dough. A rheological study of cream-cracker doughs made using both types of process has shown that fermentation weakens, but does not rearrange, intermolecular interactions. The rearrangement of storage proteins into a continuous network of gluten is achieved by the shearing action of mixing, which need only be gentle after a sufficient period of fermentation, but must be intense if prior fermentation is omitted, as in mechanical dough development. In the long fermentation process a dough with the desired characteristics was produced following a minimum of 4 h fermentation time. Dough with similar rheology was produced by mechanical development when additional water was used in the recipe. For mechanically developed cream-cracker doughs there was also an increase in the elasticity of the developed gluten. When the Chorleywood Bread Process was invented it was found that more water and less protein were required to achieve the same dough rheology as in long fermentation processes. It seems that the same relationship between mechanical dough development and long fermentation may apply to other products, such as cream-crackers. These results confirm that the technological experience gained by switching from long fermentation to mechanical dough development processes for bread production could be applied to other products such as cream-crackers. © 1997 SCI     

Semi-Sweet Biscuits: 2. Alternatives to the Use of Sodium Metabisulphite in Semi-Sweet Biscuit Production

The influence of sodium metabisulphite (SMS) and other gluten-modifying agents on the performance of a commercial biscuit flour in the production of semi-sweet biscuits has been studied. Use of a proteolytic enzyme as a gluten-modifying agent resulted in a dough with a longer mixing time than other doughs, partly as a result of mixing to a higher temperature. The extrusion time of doughs containing the proteolytic enzyme was closest to the extrusion time of doughs containing SMS. Doughs containing SMS or proteolytic enzyme produced significantly shorter extrusion times than doughs containing l -cysteine hydrochloride. Dynamic oscillatory measurements showed that for doughs made at a constant water level the lowest elastic and viscous moduli were produced by doughs containing sodium metabisulphite. Doughs containing the other gluten-modifying agents produced stronger elastic properties than those containing SMS but weaker elastic properties than doughs containing no gluten-modifying agent. The hardness of the semi-sweet biscuits produced was found to be reduced by a weakening of the rheological properties of the dough. All gluten-modifying agents reduced dough piece contraction in length during processing, although SMS was the most effective. A decrease in dough piece length during processing caused an increase in dough piece thickness and width. Use of a proteolytic enzyme or the enzyme and l -cysteine hydrochloride in combination, as gluten-modifying agents, produced biscuits closest in quality to those produced from doughs containing SMS.     

Repeatability and reproducibility of specular gloss meters in theory and practice

In order to numerically quantify and to ensure consistency of the visual appearance of the end product, many industries perform color and gloss measurements, through the results of which they define maximum tolerances during quality control. For this, they may primarily rely on precision data for repeatability and reproducibility as reported by instrument manufacturers, who develop their instruments according to standardized measurement geometries defined in international standards. This paper reports on an investigation of the inter-instrument agreement between specular gloss meters which conform to universally adopted gloss standards. Six commercially available instruments, manufactured by three different companies, and twenty-five gloss artifacts, with specular gloss values ranging between 2 and 110 gloss units (60° geometry), were selected for use in the study. The repeatability and reproducibility of the instruments were assessed according to the criteria described in ASTM D523-14 and ISO 2813:2014, and to the specifications reported by the instrument manufacturers. Ray tracing simulations were performed by use of the bidirectional reflectance distribution function measurement data of two samples, and based on the standardized optical design of the specular gloss meter, in order to get a better insight on the expected tolerances of the gloss readings from a theoretical point of view. On average, the practical results indicate that both the repeatability and reproducibility values are higher than those specified in the recommendations and by the manufacturers. Ray tracing simulations confirm this finding. While specified repeatability and reproducibility thresholds are based on ideal standards, in practice, there are parameters that can lead to significant higher deviations. Care should therefore be taken when analyzing measurement results obtained from different instruments, and when defining tolerances for evaluation of gloss measurements.     

Developing a Rail Ergonomics Questionnaire (REQUEST)

In this first of two papers the development of a shortened version of the Rail Ergonomics Questionnaire (REQUEST) is described. REQUEST has been designed to survey attitudes and opinions of railway workers on a range of human factors issues, with scales based on those used and validated elsewhere or else specially developed on the basis of studies of rail workers. Important characteristics of different roles, especially signallers, are outlined. The longer version of the questionnaire has already been used on a number of occasions for samples of 100-150. The shortened version was developed for the most recent administration of the survey to a large population. An expert group reviewed question wording, and the findings from the principal components analysis and other analyses of data from previous administrations of the survey. Improvements were made to the design and layout of the questionnaire. The effectiveness of the process for the expert review of questions is discussed. The survey was administered to high proportions of the target groups during the company safety briefing programme and achieved a sample size of almost 4000 respondents at an overall response rate of 83%. Findings from the REQUEST national survey are presented in a companion paper [Ryan, B., Wilson, J.R., Sharples, S., Clarke, T., 2008. Attitudes and opinions of railway signallers and related staff, using the Rail Ergonomics Questionnaire (REQUEST). Appl. Ergon., in press. doi:10.1016/j.apergo.2008.04.010].     

The Integrated Workload Scale (IWS): a new self-report tool to assess railway signaller workload

Network Rail, who own the railway infrastructure in the UK, have been interested in the assessment of mental workload (MWL) of signallers and control staff for some years. A new model of MWL has been proposed within which to develop a suite of new MWL analytical and empirical assessment tools. One of these is the Integrated Workload Scale (IWS), developed and tested for signallers. This paper describes the development of the IWS and its subsequent testing within two full-scale simulator trials with an NX (entry/exit) panel and an Integrated Electrical Control Centre (IECC) system, and then in the field at signal boxes. The IWS has proven to be a valuable measure of individually experienced peaks and troughs in workload over a period of time or within a particular set of scenarios. It is acceptable to signallers and maps well onto assessments of expected workload on the basis of timeline analysis and subject matter expert commentaries.     

Assessing gloss under diffuse and specular lighting

The visual sensation of gloss is built on cues deduced from the interaction between light, surfaces sunder evaluation, and surrounding conditions. Gloss is a second-order attribute of the visual appearance, this means that its perception is not directly encoded on biological sensors but constructed from the global scene in the field of view of the observer. It is then a complex quantity to measure. When most studies based on simulated samples stress on the importance of realistic observation conditions, we measure the effect of environment complexity over perception of real samples. We test two different lighting conditions: either diffuse or a combination of diffuse and collimated lighting in order to approach natural complex illumination patterns. Under both lighting conditions, we test two environments: a standard black light booth, designed according to the ASTM D4449, and a realistic office cubicle. Samples consist in a seven-level gloss scale ranging from full matt to high gloss. These are presented to observers through pair comparison protocol, according to a maximum likelihood difference scaling algorithm. Our results confirm that gloss constancy is maintained even if the convergence of illumination varies. We however measure that the constancy is lost for matt samples perception.